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1.
Scand J Med Sci Sports ; 27(12): 1569-1575, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28033657

RESUMEN

Enhanced physical performance following whole-body vibration (WBV) has been attributed to increased muscle activity; however, few studies have measured the mechanisms underlying these changes. The objective of this study was to measure the responsiveness of the Ia pathway as well as contractile properties in 16 young adults (24±2 years, eight men, eight women) following repeated bouts of acute WBV (45 Hz, 2 mm). Hoffman reflexes (H-reflex), compound muscle action potentials (M-wave), and twitch contractile properties were measured prior to and immediately following five 1-minute WBV exposures, and at 3, 5, 10, and 20 minute post-WBV. M-wave and H-reflex amplitudes decreased by 8% (P<.001) and by 46% (P<.05), respectively, whereas peak twitch torque decreased by 9% (P<.01) and rate of twitch torque development slowed 8% (P<.05). Percent voluntary activation and maximal plantar flexor torque were unchanged as a consequence of WBV (P>.05). In response to acute WBV, the root mean square of the soleus electromyography signal (EMGRMS ) increased by 8%, while the EMGRMS of the lateral gastrocnemius increased by 3% (P<.05). These data indicate that the responsiveness of the Ia pathway is diminished and contractile function is impaired immediately following WBV, and that the neural mechanisms underlying improved performance following WBV lie in alternative hypotheses possibly involving spindle disfacilitation or Golgi afferent modulation.


Asunto(s)
Contracción Muscular/fisiología , Músculo Esquelético/fisiología , Vibración , Adulto , Electromiografía , Potenciales Evocados Motores , Femenino , Pie , Reflejo H , Humanos , Masculino , Torque , Adulto Joven
2.
Ann Oncol ; 27(5): 868-74, 2016 05.
Artículo en Inglés | MEDLINE | ID: mdl-26912557

RESUMEN

BACKGROUND: Radium-223 dichloride (radium-223), a first-in-class α-emitting radiopharmaceutical, is recommended in both pre- and post-docetaxel settings in patients with castration-resistant prostate cancer (CRPC) and symptomatic bone metastases based on overall survival benefit demonstrated in the phase III ALSYMPCA study. ALSYMPCA included prospective measurements of health-related quality of life (QOL) using two validated instruments: the general EuroQoL 5D (EQ-5D) and the disease-specific Functional Assessment of Cancer Therapy-Prostate (FACT-P). PATIENTS AND METHODS: Analyses were conducted to determine treatment effects of radium-223 plus standard of care (SOC) versus placebo plus SOC on QOL using FACT-P and EQ-5D. Outcomes assessed were percentage of patients experiencing improvement, percentage of patients experiencing worsening, and mean QOL scores during the study. RESULTS: Analyses were carried out on the intent-to-treat population of patients randomized to receive radium-223 (n = 614) or placebo (n = 307). The mean baseline EQ-5D utility and FACT-P total scores were similar between treatment groups. A significantly higher percentage of patients receiving radium-223 experienced meaningful improvement in EQ-5D utility score on treatment versus placebo {29.2% versus 18.5%, respectively; P = 0.004; odds ratio (OR) = 1.82 [95% confidence interval (CI) 1.21-2.74]}. Findings were similar for FACT-P total score [24.6% versus 16.1%, respectively; P = 0.020; OR = 1.70 (95% CI 1.08-2.65)]. A lower percentage of patients receiving radium-223 experienced meaningful worsening versus placebo measured by EQ-5D utility score and FACT-P total score. Prior docetaxel use and current bisphosphonate use did not affect these findings. Treatment was a significant predictor of EQ-5D utility score, with radium-223 associated with higher scores versus placebo (0.56 versus 0.50, respectively; P = 0.002). Findings were similar for FACT-P total score (99.08 versus 95.22, respectively; P = 0.004). CONCLUSIONS: QOL data from ALSYMPCA demonstrated that improved survival with radium-223 is accompanied by significant QOL benefits, including a higher percentage of patients with meaningful QOL improvement and a slower decline in QOL over time in patients with CRPC.


Asunto(s)
Neoplasias Óseas/radioterapia , Neoplasias de la Próstata Resistentes a la Castración/radioterapia , Radiofármacos/administración & dosificación , Radio (Elemento)/administración & dosificación , Anciano , Neoplasias Óseas/tratamiento farmacológico , Neoplasias Óseas/secundario , Terapia Combinada , Docetaxel , Método Doble Ciego , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Neoplasias de la Próstata Resistentes a la Castración/tratamiento farmacológico , Neoplasias de la Próstata Resistentes a la Castración/patología , Calidad de Vida , Radioisótopos/administración & dosificación , Radioisótopos/efectos adversos , Radiofármacos/efectos adversos , Radio (Elemento)/efectos adversos , Nivel de Atención , Taxoides/administración & dosificación , Resultado del Tratamiento
3.
Antimicrob Agents Chemother ; 59(10): 6017-25, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26195509

RESUMEN

Analysis of data pooled from multiple phase 2 (SILEN-C1 to 3) and phase 3 studies (STARTVerso1 to 4) of the hepatitis C virus (HCV) nonstructural protein 3/4A (NS3/4A) protease inhibitor faldaprevir plus pegylated interferon alpha/ribavirin (PR) provides a comprehensive evaluation of baseline and treatment-emergent NS3/4A amino acid variants among HCV genotype-1 (GT-1)-infected patients. Pooled analyses of GT-1a and GT-1b NS3 population-based pretreatment sequences (n = 3,124) showed that faldaprevir resistance-associated variants (RAVs) at NS3 R155 and D168 were rare (<1%). No single, noncanonical NS3 protease or NS4A cofactor baseline polymorphism was associated with a reduced sustained virologic response (SVR) to faldaprevir plus PR, including Q80K. The GT-1b NS3 helicase polymorphism T344I was associated with reduced SVR to faldaprevir plus PR (P < 0.0001) but was not faldaprevir specific, as reduced SVR was also observed with placebo plus PR. Among patients who did not achieve SVR and had available NS3 population sequences (n = 507 GT-1a; n = 349 GT-1b), 94% of GT-1a and 83% of GT-1b encoded faldaprevir treatment-emergent RAVs. The predominant GT-1a RAV was R155K (88%), whereas GT-1b encoded D168 substitutions (78%) in which D168V was predominant (67%). The novel GT-1b NS3 S61L substitution emerged in 7% of virologic failures as a covariant with D168V, most often among the faldaprevir breakthroughs; S61L in combination with D168V had a minimal impact on faldaprevir susceptibility compared with that for D168V alone (1.5-fold difference in vitro). The median time to loss of D168 RAVs among GT-1b-infected patients who did not have a sustained virologic response at 12 weeks posttreatment (non-SVR12) after virologic failure was 5 months, which was shorter than the 14 months for R155 RAVs among GT-1a-infected non-SVR12 patients, suggesting that D168V is less fit than R155K in the absence of faldaprevir selective pressure.


Asunto(s)
Antivirales/uso terapéutico , Hepatitis C Crónica/tratamiento farmacológico , Interferón-alfa/uso terapéutico , Oligopéptidos/uso terapéutico , Polietilenglicoles/uso terapéutico , Polimorfismo Genético , Ribavirina/uso terapéutico , Tiazoles/uso terapéutico , Sustitución de Aminoácidos , Ácidos Aminoisobutíricos , Proteínas Portadoras/antagonistas & inhibidores , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Método Doble Ciego , Farmacorresistencia Viral/efectos de los fármacos , Farmacorresistencia Viral/genética , Expresión Génica , Genotipo , Hepacivirus/efectos de los fármacos , Hepacivirus/genética , Hepacivirus/metabolismo , Hepatitis C Crónica/virología , Humanos , Péptidos y Proteínas de Señalización Intracelular , Leucina/análogos & derivados , Mutación , Prolina/análogos & derivados , Quinolinas , Proteínas Recombinantes/uso terapéutico , Resultado del Tratamiento , Proteínas no Estructurales Virales/antagonistas & inhibidores , Proteínas no Estructurales Virales/genética , Proteínas no Estructurales Virales/metabolismo
4.
Artículo en Alemán | MEDLINE | ID: mdl-24170083

RESUMEN

The term individualised medicine, also called personalised medicine, is commonly used as an equivalent to stratified medicine. However, this is erroneous since quite often it is forgotten that especially biological medicinal products have other aspects of individualization that go beyond mere stratification. The principles of stratified medicine have been applied for biological medicinal products for many years. A historical example is diphtheria antitoxin made from horse serum, while current examples are transfusion of red blood cells and the administration of factor VIII in haemophilia A. The stratifying aspects of these medicinal products are given by the following considerations: diphtheria antitoxin is only administered after a diagnosis of diphtheria and not in other forms of tonsillitis, red blood cells should only be transfused once blood group compatibility as been established and factor VIII replacement is only administered in haemophilia A as opposed to other acquired or hereditary disease of the coagulation system. The peculiarities of biological medicinal products, in particular the inherent variability of the drug, are especially important for autologous cellular medicinal products. In addition to the expected variability of the biological source material there is interindividual variability of patients as cell donors, which make definition of specifications and determination of criteria for pharmaceutical quality and potency tests difficult. Therapy with modified autologous cells, a common and important application of advanced therapy medicinal products, is exemplary for the special considerations that must be made when evaluating pharmaceutical quality, mode of action and toxicological properties of the biological medicine. The clinical investigation of advanced therapy medicinal products with the intent of demonstrating safety and efficacy is particularly challenging because of the complexity of therapy, which often involves invasive interventions. The development of biomarkers accelerates the process towards stratified or individualised therapies. Increased requirements for companion diagnostics are a possible consequence. Progress in analytical processes and in biotechnology make a higher degree of individualization likely, possibly to the degree that medicinal products will be individually manufactured for each patient. Current principles of medicinal product testing and market authorization may be applicable only with limitations, because the individual medicinal products are not uniform and are not repeatedly manufactured. The assessment of the process, performed on several different medicinal products manufactured by the same process could potentially serve as a basis for the assessment. For the evaluation of risk for the patient in clinical trials new concepts must be considered, which can be facilitated by interaction of regulatory authorities and developers.


Asunto(s)
Productos Biológicos/uso terapéutico , Diseño de Fármacos , Monitoreo de Drogas/métodos , Técnicas de Diagnóstico Molecular/métodos , Terapia Molecular Dirigida/métodos , Farmacogenética/métodos , Medicina de Precisión/métodos , Humanos , Medición de Riesgo
5.
Eur Geriatr Med ; 13(1): 233-241, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34324144

RESUMEN

PURPOSE: The number of severely injured patients exceeding the age of 60 has shown a steep increase within the last decades. These patients present with numerous co-morbidities, polypharmacy, and increased frailty requiring an adjusted treatment approach. In this study, we establish an overview of changes we observed in demographics of older severe trauma patients from 2002 to 2017. METHODS: A descriptive analysis of the data from the TraumaRegister DGU® (TR-DGU) was performed. Patients admitted to a level one trauma center in Germany, Austria and Switzerland between 2002 and 2017, aged 60 years or older and with an injury severity score (ISS) over 15 were included. Patients were stratified into subgroups based on the admission: 2002-2005 (1), 2006-2009 (2), 2010-2013 (3) and 2014-2017 (4). Trauma and patient characteristics, diagnostics, treatment and outcome were compared. RESULTS: In total 27,049 patients with an average age of 73.9 years met the inclusion criteria. The majority were males (64%), and the mean ISS was 27.4. The proportion of patients 60 years or older [(23% (1) to 40% (4)] rose considerably over time. Trauma mechanisms changed over time and more specifically low falls (< 3 m) rose from 17.6% (1) to 40.1% (4). Altered injury patterns were also identified. Length-of-stay decreased from 28.9 (1) to 19.5 days (4) and the length-of-stay on ICU decreased from 17.1 (1) to 12.7 days (4). Mortality decreased from 40.5% (1) to 31.8% (4). CONCLUSION: Length of stay and mortality decreased despite an increase in patient age. We ascribe this observation mainly to increased use of diagnostic tools, improved treatment algorithms, and the implementation of specialized trauma centers for older patients allowing interdisciplinary care.


Asunto(s)
Traumatismo Múltiple , Anciano , Femenino , Alemania/epidemiología , Humanos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Traumatismo Múltiple/diagnóstico , Traumatismo Múltiple/epidemiología , Traumatismo Múltiple/terapia , Sistema de Registros , Estudios Retrospectivos
6.
Trauma Case Rep ; 32: 100432, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33665323

RESUMEN

INTRODUCTION: False traumatic aneurysm (FTA) or pseudoaneurysm and traumatic arteriovenous fistulas (TAVF) are rare pathologies in civilian trauma and mainly result from stabs or gunshot wounds. The posterior tibial artery as site of trauma is very rare. PRESENTATION OF CASE: We report on a 39-year old female patient who was suffering from combined FTA and TAVF of the posterior tibial artery after falling into a wine glass. CT-imaging as well as duplex ultrasound and selective arteriography were performed, and two stent-grafts were inserted. DISCUSSION: Based on the presented case, incidence of the described pathology, treatment options and outcomes are discussed. CONCLUSION: Adequate imaging in penetrating wounds to the extremities is crucial in order to provide diagnosis and treatment of concomitant lesions.

7.
J Exp Med ; 128(5): 1137-55, 1968 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-5303065

RESUMEN

The present study demonstrates that a granule fraction derived from human polymorphonuclear leukocytes possesses elastinolytic activity, and that the latter can be separated from the collagenase present in these cells. Properties of the human leukocyte elastase differ sufficiently from those of pancreatic elastases of different species as to suggest that the former enzyme is a distinct and separate entity. Thus, soybean trypsin inhibitor and salivary kallikrein inhibitor (Trasylol) fail to inhibit elastolysis by the pancreatic enzyme, but do inhibit the leukocyte elastinolytic agent. Elastolysis by human leukocyte granule extract does not show significant salt inhibition, whereas that catalyzed by pancreatic elastase is markedly reduced when ionic strength is increased to physiological levels. The leukocyte granule extract is at least 10 times more resistant to serum elastase inhibitor than is the purified pancreatic enzyme. Both enzymes show optimal elastolysis above pH 8.5, but the leukocyte factor still retains 50% of its maximal elastolytic activity at pH 6-7; whereas the activity of the pancreatic enzyme falls to 10% or less of its maximal value under the same conditions. The foregoing characteristics of the human leukocyte elastase suggest that it, rather than pancreatic (serum) elastase, may mediate pathological elastolysis during acute arteritis in man. In keeping with this suggestion, the present experiments also show that elastica staining of human arterial vessels is reduced by incubation of tissues with human leukocyte granule extracts in vitro.


Asunto(s)
Inflamación/enzimología , Leucocitos/enzimología , Lisosomas/enzimología , Elastasa Pancreática/metabolismo , Adulto , Aprotinina/farmacología , Sangre , Colágeno , Tejido Elástico/efectos de los fármacos , Hemoglobinas/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Técnicas In Vitro , Leucocitos/análisis , Masculino , Páncreas/enzimología , Elastasa Pancreática/análisis , Elastasa Pancreática/antagonistas & inhibidores , Péptido Hidrolasas/farmacología , Proteínas/análisis , Cloruro de Sodio/farmacología , Extractos de Tejidos
8.
J Exp Med ; 193(11): 1269-84, 2001 Jun 04.
Artículo en Inglés | MEDLINE | ID: mdl-11390434

RESUMEN

T cell receptor (TCR)-interacting molecule (TRIM) is a recently identified transmembrane adaptor protein, which is exclusively expressed in T cells. Here we demonstrate that in mature T cells, TRIM preferentially interacts with the TCR via the TCR-zeta chains and to a lesser extent via the CD3-straightepsilon/gamma heterodimer. Transient or stable overexpression of TRIM in Jurkat T cells results in enhancement of TCR expression on the cell surface and elevated induction of Ca(2+) mobilization after T cell activation. TRIM-mediated upregulation of TCR expression results from inhibition of spontaneous TCR internalization and stabilization of TCR complexes on the cell surface. Collectively, our data identify TRIM as a novel integral component of the TCR complex and suggest that one function of TRIM might be to modulate the strength of signals transduced through the TCR through regulation of TCR expression on the cell surface.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Proteínas Portadoras/fisiología , Proteínas de la Membrana/química , Proteínas de la Membrana/fisiología , Receptores de Antígenos de Linfocitos T/química , Receptores de Antígenos de Linfocitos T/fisiología , Transducción de Señal , Secuencia de Aminoácidos , Animales , Células COS , Calcio/metabolismo , Dimerización , Humanos , Células Jurkat , Datos de Secuencia Molecular
9.
J Exp Med ; 191(9): 1591-604, 2000 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-10790433

RESUMEN

According to a recently proposed hypothesis, initiation of signal transduction via immunoreceptors depends on interactions of the engaged immunoreceptor with glycosphingolipid-enriched membrane microdomains (GEMs). In this study, we describe a novel GEM-associated transmembrane adaptor protein, termed phosphoprotein associated with GEMs (PAG). PAG comprises a short extracellular domain of 16 amino acids and a 397-amino acid cytoplasmic tail containing ten tyrosine residues that are likely phosphorylated by Src family kinases. In lymphoid cell lines and in resting peripheral blood alpha/beta T cells, PAG is expressed as a constitutively tyrosine-phosphorylated protein and binds the major negative regulator of Src kinases, the tyrosine kinase Csk. After activation of peripheral blood alpha/beta T cells, PAG becomes rapidly dephosphorylated and dissociates from Csk. Expression of PAG in COS cells results in recruitment of endogenous Csk, altered Src kinase activity, and impaired phosphorylation of Src-specific substrates. Moreover, overexpression of PAG in Jurkat cells downregulates T cell receptor-mediated activation of the transcription factor nuclear factor of activated T cells. These findings collectively suggest that in the absence of external stimuli, the PAG-Csk complex transmits negative regulatory signals and thus may help to keep resting T cells in a quiescent state.


Asunto(s)
Glicoesfingolípidos/metabolismo , Activación de Linfocitos , Proteínas de la Membrana/metabolismo , Fosfoproteínas/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Linfocitos T/inmunología , Proteínas Adaptadoras Transductoras de Señales , Secuencia de Aminoácidos , Complejo CD3/metabolismo , Proteína Tirosina Quinasa CSK , Clonación Molecular , ADN Complementario/genética , Humanos , Proteínas de la Membrana/genética , Datos de Secuencia Molecular , Fosfoproteínas/genética , Unión Proteica , Receptores de Antígenos de Linfocitos T/metabolismo , Transducción de Señal , Familia-src Quinasas
10.
Forensic Sci Int ; 315: 110434, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-32758788

RESUMEN

BACKGROUND: Point-of-collection testing (POCT) devices for psychoactive substance detection through oral fluid samples are used in several countries for traffic enforcement. However, the reported reliability of such devices is quite heterogeneous among studies, and evaluating and comparing their analytical performance is of paramount importance to guide enforcement policies. AIM: To evaluate the analytical reliability of four POCT devices for the detection of cocaine and cannabinoids using oral fluid samples of Brazilian drivers. METHOD: A total of 168 drivers were recruited during standard roadblockfI procedures in Southern Brazil. Subjects were screened using one of the following POCT devices: the DDS2™, the DOA MultiScreen™, the Dräger Drug Test 5000™ and the Multi-Drug Multi-Line Twist Screen Device™ (MDML). Results of the screening tests were compared with chromatographic analyses in order to obtain the reliability parameters. RESULTS: The prevalence of confirmed positive samples for cocaine and cannabinoids were 9 % and 4.4 %, respectively. For cocaine, three POCT devices (MDML™, Dräger DrugTest 5000™, DOA MultiScreen™) showed good reliability, greater than 80 % of performance measures, using guidelines for research on drugged driving published by Walsh et al. (cutoff 10ng/mL). However, for cannabinoids, the devices had low reliability-only Dräger DrugTest 5000™ had good performance using cut-offs proposed by Walsh et al. (cutoff 2ng/mL). CONCLUSION: We observed a high prevalence of drivers testing positive for cocaine and cannabinoids. Most devices achieved good reliability performance for cocaine detection using cutoffs proposed by Walsh et al. or using the device's own cutoff. Instead, the reliability for cannabinoid detection obtained the desired parameters in just one device using cut-offs proposed by Walsh et al. and its own cutoff. Difficulties in detecting cannabinoids at the roadside should be better evaluated before the implementation of such tests.


Asunto(s)
Cannabinoides/análisis , Cocaína/análisis , Conducir bajo la Influencia , Saliva/química , Detección de Abuso de Sustancias/métodos , Adolescente , Adulto , Brasil , Femenino , Humanos , Drogas Ilícitas/análisis , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Adulto Joven
11.
J Nutr Health Aging ; 21(3): 299-306, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28244570

RESUMEN

OBJECTIVE: To investigate causal factors of functional impairment in old age in a longitudinal approach. DESIGN: A population-based prospective cohort study. SETTING: Elderly individuals were recruited via GP offices at six study centers in Germany. They were observed every 1.5 years over six waves. PARTICIPANTS: Three thousand two hundred fifty-six people aged 75 years and older at baseline. MEASUREMENTS: Functional impairment was quantified by the Lawton and Brody Instrumental Activities of Daily Living scale (IADL) and the Barthel-Index (BI). RESULTS: Fixed effects regressions revealed that functional impairment (IADL; BI) increased significantly with ageing (ß=-.2; ß=-1.1), loss of a spouse (ß= .5; ß=-3.1), not living alone in private household (ß=-1.2; ß=-5.5), depression (solely significant for IADL: ß= .6) and dementia (ß=-2.3; ß=-18.2). The comorbidity score did not affect functional impairment. CONCLUSION: Our findings underline the relevance of changes in sociodemographic variables as well as the occurrence of depression or dementia for functional impairment. While several of these causal factors for functional decline in the oldest old are inevitable, some may not be, such as depression. Therefore, developing interventional strategies to prevent depression might be a fruitful approach in order to delay functional impairment in old age.


Asunto(s)
Actividades Cotidianas , Envejecimiento/fisiología , Disfunción Cognitiva/fisiopatología , Demencia/fisiopatología , Depresión/psicología , Anciano , Anciano de 80 o más Años , Envejecimiento/psicología , Estudios de Cohortes , Comorbilidad , Demencia/prevención & control , Femenino , Alemania , Humanos , Estudios Longitudinales , Masculino , Estudios Prospectivos
12.
J Natl Cancer Inst ; 63(2): 375-8, 1979 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-313471

RESUMEN

The distribution of membrane antigens on 6 DBA/2-derived tumors (L1210, L5178Y, P815, ABLS 11, ABLS 12, and ABLS 13) was studied by direct cytotoxicity and quantitative absorption assays. Lyb-4.1 antigen was found solely on the L1210 tumor. Iad antigens were absent from all tumors, and H-2Kd and H-2Dd antigens were present on all tumors. Immunoglobulin was adsorbed to the ascites tumors and lost after 3 days or more in tissue culture. These studies were performed to characterize the distribution of DBA/2 membrane antigens on DBA/2-derived tumors as a base line for functional and chemical studies with these tumors and with their solubilized proteins.


Asunto(s)
Antígenos de Neoplasias , Antígenos de Superficie , Linfocitos B/inmunología , Isoantígenos , Linfoma/inmunología , Animales , Antígenos H-2 , Leucemia L1210/inmunología , Leucemia Experimental/inmunología , Proteínas de la Membrana/inmunología , Ratones , Ratones Endogámicos , Proteínas de Neoplasias/inmunología
13.
Biochim Biophys Acta ; 601(1): 47-53, 1980 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-7407164

RESUMEN

The degree of lateral crystal-like order between hydrocarbon chains in biomembrane systems can be estimated from Raman measurements in the C-H stretching region. Observations of the temperature dependence of the Raman spectra of crystalline n-C16H34 and the urea clathrate of n-C16H34 have enabled us to separate to some extent the overlapping effects of chain packing and chain mobility, effects that are normally not distinguished in considering lateral order. The mobility is associated with the freedom of an extended chain to rotate and twist about its long axis. A high degree of such motion must be ascribed to n-C16H34 in a urea clathrate in order to explain the unusual temperature behavior observed for Raman bands at 2885 and 1174 cm-1. Comparison of the temperature behavior of the Raman spectra of the clathrate with that of crystalline n-C16H34 permits the effects due to packing and to mobility to be distinguished. The same effects can be expected to be present in the Raman spectra of biomembranes.


Asunto(s)
Alcanos , Membranas/ultraestructura , Urea , Modelos Biológicos , Conformación Molecular , Espectrometría Raman , Temperatura
14.
Circulation ; 101(3): 239-43, 2000 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-10645918

RESUMEN

BACKGROUND: In the presence of ST-elevation myocardial infarction, patients with successful epicardial reperfusion (TIMI 3 flow) but persistent ST elevation on a 12-lead ECG are at high risk for subsequent death and left ventricular dysfunction. In the TIMI 14 trial, a dose-ranging angiographic study, combined therapy with abciximab plus reduced-dose tPA enhanced the speed and efficacy of epicardial reperfusion. We determined whether the combination of abciximab plus reduced-dose tPA provided additional benefit in terms of myocardial reperfusion, as evidenced by greater resolution of ST elevation. METHODS AND RESULTS: All 346 patients with interpretable baseline and 90-minute ECGs, treated with either tPA alone or abciximab plus reduced-dose tPA (combination therapy), were included. Patients receiving combination therapy (n=221) had a 59% rate of complete (>/=70%) ST resolution at 90 minutes versus 37% in those treated with tPA alone (n=125) (P<0.0001). When the analysis was limited to patients with TIMI 3 flow, patients treated with combination therapy (n=151) remained significantly more likely to achieve complete ST resolution than those receiving tPA alone (n=80) (69% versus 44%; P=0.0002). CONCLUSIONS: Combination therapy with abciximab and reduced-dose tPA improves myocardial (microvascular) reperfusion, as reflected in greater ST-segment resolution, in addition to epicardial flow. This finding may translate into improved clinical outcomes by enhancing myocardial salvage.


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Circulación Coronaria/efectos de los fármacos , Electrocardiografía , Fragmentos Fab de Inmunoglobulinas/administración & dosificación , Infarto del Miocardio/tratamiento farmacológico , Reperfusión Miocárdica , Activador de Tejido Plasminógeno/administración & dosificación , Abciximab , Quimioterapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/fisiopatología
15.
Circulation ; 101(23): 2690-5, 2000 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-10851205

RESUMEN

BACKGROUND: We evaluated platelet activation and aggregation in patients with acute myocardial infarction (AMI) treated with thrombolytic therapy alone or with reduced-dose thrombolysis and concomitant abciximab. METHODS AND RESULTS: The study was performed in 20 control subjects and 51 patients with AMI before and after reperfusion with either alteplase or reteplase or reduced doses of these agents with concomitant abciximab. Platelet activation was assayed by platelet surface expression of P-selectin. Turbidometric platelet aggregation in response to ADP was measured in patients before thrombolytic therapy and 90 minutes and 24 hours after the beginning of thrombolytic therapy. P-selectin expression was greater at baseline in patients than normal control subjects (30.4% versus 9. 8%, P<0.0001) but was identical between the 2 groups after stimulation with ADP (64.4% versus 69.3%, P=0.37). However, at 24 hours, basal P-selectin expression declined in patients (P=0.0025 versus baseline), whereas ADP-stimulated P-selectin expression was lower in patients than in control subjects (48% versus 69%, P=0. 0004). When combined with reduced doses of either alteplase or reteplase, abciximab achieved 91% and 83% inhibition of 5 and 20 micromol/L ADP-induced platelet aggregation, which decreased to 46% and 40%, respectively, at 24 hours. No appreciable difference in the platelet inhibition profile of abciximab was observed between the 2 thrombolytics. CONCLUSIONS: Platelet activation and aggregation are heightened in the setting of thrombolysis for AMI. Despite this enhanced level of platelet activation, abciximab, combined with a reduced-dose thrombolytic, inhibited platelet aggregation similarly to the level reported in elective settings.


Asunto(s)
Anticuerpos Monoclonales/administración & dosificación , Fragmentos Fab de Inmunoglobulinas/administración & dosificación , Infarto del Miocardio/tratamiento farmacológico , Activadores Plasminogénicos/administración & dosificación , Inhibidores de Agregación Plaquetaria/administración & dosificación , Agregación Plaquetaria/efectos de los fármacos , Terapia Trombolítica , Activador de Tejido Plasminógeno/administración & dosificación , Abciximab , Anciano , Plaquetas/efectos de los fármacos , Plaquetas/metabolismo , Angiografía Coronaria , Femenino , Fibrinolíticos/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Selectina-P/biosíntesis , Proteínas Recombinantes/administración & dosificación , Resultado del Tratamiento
16.
Circulation ; 99(21): 2720-32, 1999 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-10351964

RESUMEN

BACKGROUND: The TIMI 14 trial tested the hypothesis that abciximab, the Fab fragment of a monoclonal antibody directed to the platelet glycoprotein (GP) IIb/IIIa receptor, is a potent and safe addition to reduced-dose thrombolytic regimens for ST-segment elevation MI. METHODS AND RESULTS: Patients (n=888) with ST-elevation MI presenting <12 hours from onset of symptoms were treated with aspirin and randomized initially to either 100 mg of accelerated-dose alteplase (control) or abciximab (bolus 0.25 mg/kg and 12-hour infusion of 0.125 microg. kg-1. min-1) alone or in combination with reduced doses of alteplase (20 to 65 mg) or streptokinase (500 000 U to 1.5 MU). Control patients received standard weight-adjusted heparin (70-U/kg bolus; infusion of 15 U. kg-1. h-1), whereas those treated with a regimen including abciximab received low-dose heparin (60-U/kg bolus; infusion of 7 U. kg-1. h-1). The rate of TIMI 3 flow at 90 minutes for patients treated with accelerated alteplase alone was 57% compared with 32% for abciximab alone and 34% to 46% for doses of streptokinase between 500 000 U and 1.25 MU with abciximab. Higher rates of TIMI 3 flow at both 60 and 90 minutes were observed with increasing duration of administration of alteplase, progressing from a bolus alone to a bolus followed by either a 30- or 60-minute infusion (P<0.02). The most promising regimen was 50 mg of alteplase (15-mg bolus; infusion of 35 mg over 60 minutes), which produced a 76% rate of TIMI 3 flow at 90 minutes and was tested subsequently in conjunction with either low-dose or very-low-dose (30-U/kg bolus; infusion of 4 U. kg-1. h-1) heparin. TIMI 3 flow rates were significantly higher in the 50-mg alteplase plus abciximab group versus the alteplase-only group at both 60 minutes (72% versus 43%; P=0.0009) and 90 minutes (77% versus 62%; P=0.02). The rates of major hemorrhage were 6% in patients receiving alteplase alone (n=235), 3% with abciximab alone (n=32), 10% with streptokinase plus abciximab (n=143), 7% with 50 mg of alteplase plus abciximab and low-dose heparin (n=103), and 1% with 50 mg of alteplase plus abciximab with very-low-dose heparin (n=70). CONCLUSIONS: Abciximab facilitates the rate and extent of thrombolysis, producing early, marked increases in TIMI 3 flow when combined with half the usual dose of alteplase. This improvement in reperfusion with alteplase occurred without an increase in the risk of major bleeding. Substantial reductions in heparin dosing may reduce the risk of bleeding even further. Modest improvements in TIMI 3 flow were seen when abciximab was combined with streptokinase, but there was an increased risk of bleeding.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Fragmentos Fab de Inmunoglobulinas/uso terapéutico , Infarto del Miocardio/terapia , Inhibidores de Agregación Plaquetaria/uso terapéutico , Terapia Trombolítica , Abciximab , Adolescente , Adulto , Anciano , Anticuerpos Monoclonales/efectos adversos , Terapia Combinada , Angiografía Coronaria , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Fragmentos Fab de Inmunoglobulinas/efectos adversos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/diagnóstico por imagen , Inhibidores de Agregación Plaquetaria/efectos adversos
17.
Braz J Biol ; 75(4): 932-5, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26675909

RESUMEN

Cadmium, cobalt, chromium, copper, manganese, nickel, zinc and lead concentrations were detected in feathers of Buff-breasted Sandpipers (Calidris subruficollis) captured during the non-breeding season and analyzed with relationship to body mass. Of these metals tested for, only copper levels (2.28 µg/g) were positively correlated with bird body mass. Zinc levels showed higher concentration (67.97 µg/g) than the other metals, and cadmium levels showed the lowest concentration (0.14 µg/g). Trace element concentrations were below toxicity levels for all tested chemicals and we suggest that this probably reflects that essential elements are maintained there by normal homeostatic mechanism and that no excessive environmental exposure to these elements during migration or on the wintering area is suggested by these results.


Asunto(s)
Charadriiformes/metabolismo , Exposición a Riesgos Ambientales , Contaminantes Ambientales/metabolismo , Plumas/química , Metales Pesados/metabolismo , Animales , Monitoreo del Ambiente , Femenino , Masculino
18.
Cell Prolif ; 35 Suppl 1: 93-102, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12139712

RESUMEN

Oral mucositis is a common, dose-limiting, acute toxicity of radiation therapy administered for the treatment of cancers of the head and neck. Accumulating data would suggest that the pathogenesis of mucositis is complex and involves the sequential interaction of all cell types of the oral mucosa, as well as a number of cytokines and elements of the oral environment. While a number of studies have reported on gene expression of particular cell types in response to radiation, the overall response of irradiated mucosa has only been evaluated in a limited way. The present study was undertaken to evaluate the expression of a target group of genes using RNA quantification assays and, more broadly, to assess patterns of mucosal gene expression using DNA microarray hybridization. Our results demonstrate the sequential upregulation of a series of genes that, when taken collectively, suggest an intricate functional interaction.


Asunto(s)
Mucosa Bucal/fisiopatología , Análisis de Secuencia por Matrices de Oligonucleótidos , Traumatismos Experimentales por Radiación/genética , Estomatitis/genética , Animales , Cricetinae , ADN Polimerasa III/genética , Modelos Animales de Enfermedad , Expresión Génica/efectos de la radiación , Proteínas HSP70 de Choque Térmico/genética , Proteínas HSP90 de Choque Térmico/genética , Masculino , Mesocricetus , Óxido Nítrico Sintasa/genética , Óxido Nítrico Sintasa de Tipo II , Traumatismos Experimentales por Radiación/fisiopatología , Estomatitis/fisiopatología , Factor de Necrosis Tumoral alfa/genética , Proteína p53 Supresora de Tumor/genética
19.
J Comp Neurol ; 302(4): 779-91, 1990 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-1964466

RESUMEN

The response of retinal microglial cells, which accompanies retrograde degeneration of ganglion cell axons and perikarya (induced by transection of the optic nerve), was studied in whole-mounted rabbit retinae labeled enzyme-histochemically for nucleoside diphosphatase (NDPase), which is a microglial cell marker. A few days after transection, the number of microglial cells/mm2, as well as their staining intensity, began to increase in the inner plexiform layer. The mosaic-like distribution of the star-shaped microglial cells present in the inner plexiform layer of a normal rabbit retina was preserved during ganglion cell degeneration. As in the normal retina, processes of individual cells never overlapped with those of neighboring cells in the inner plexiform layer because individual cells in the "degenerating" retina acquired shorter processes, i.e., the cells occupied a smaller territory compared to the normal retina. In the nerve fiber layer the number and staining intensity of NDPase-labeled microglial cell processes (most of which are aligned in parallel with degenerating ganglion cell axons) transiently increased and returned to normal values by 5 months post-transection. Microglial cells that are not detectably NDPase labeled in the outer plexiform layer of a normal rabbit retina acquire intense staining a few days after the nerve is cut. The functional significance of the increased NDPase activity in the plasma membrane of microglial cells during degeneration remains to be determined.


Asunto(s)
Ácido Anhídrido Hidrolasas , Neuroglía/patología , Traumatismos del Nervio Óptico , Conejos/anatomía & histología , Retina/patología , Animales , Recuento de Células , Degeneración Nerviosa , Monoéster Fosfórico Hidrolasas/análisis
20.
J Comp Neurol ; 312(2): 175-92, 1991 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-1748726

RESUMEN

Rabbit retinae were stained with antibodies to glial fibrillary acidic protein (GFAP) at various times up to 5 months after complete unilateral intraorbital optic nerve transection, which is known to induce degeneration of ganglion cell axons and perikarya in the retina. A transient immunoreactivity for GFAP was observed in Müller glial cells that normally lack this marker. Müller-cell GFAP immunoreactivity became detectable 4 days after the lesion, but Müller cells were no longer labeled 3 months later. GFAP-labeled astrocytes located in the nerve fiber layer showed no change in immunoreactivity at any stage after transection. Application of horseradish peroxidase to the left and right superior colliculus of a rabbit whose optic nerve had been transected unilaterally 2 years before confirmed the completeness of the transection. Yet electron microscopy showed the presence of some healthy-looking ganglion cell axons in the lesioned retina, although these cells were deprived of their target. Labeling retinal wholemounts with neurofilament antibodies confirmed the presence of some ganglion cell axons and perikarya in the retina more than 2 years after transection. The course of these axons suggested that they were remnants of axons. Using antibodies to galactocerebroside (GC) we found that, as in the normal rabbit, these persisting ganglion cell axons were myelinated in the medullary rays. Although many ganglion cell axons had disappeared after 2 years, the number of neuroglial cells (including astrocytes and oligodendrocytes) present in the medullary ray region was not altered. The cell bodies of some oligodendrocytes were covered with a myelin sheath, an aberrant feature not seen normally.


Asunto(s)
Neuroglía/fisiología , Nervio Óptico/fisiología , Órbita/inervación , Conejos/fisiología , Retina/fisiología , Células Ganglionares de la Retina/fisiología , Animales , Biomarcadores , Recuento de Células , Desnervación , Peroxidasa de Rábano Silvestre , Inmunohistoquímica , Microscopía Electrónica , Degeneración Nerviosa , Fibras Nerviosas/ultraestructura , Neuroglía/ultraestructura , Retina/citología , Células Ganglionares de la Retina/ultraestructura
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